What innovation, introduced by Ronalds and Brooke in 1846, eased the burden of continuous magnetic observation?

Answer

The use of photography to continuously record magnet movements

Magnetographs invented by Francis Ronalds and Charles Brooke utilized photography to automatically log the movements of the attached magnet, allowing for continuous data recording.

What innovation, introduced by Ronalds and Brooke in 1846, eased the burden of continuous magnetic observation?
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